Dirac Fast Scramblers

TL;DR

This paper introduces higher-dimensional generalizations of the Sachdev-Ye-Kitaev model using Gross-Neveu-Yukawa models, revealing critical solutions with maximal chaos and anomalous dimensions in 1+1 and 2+1 dimensions.

Contribution

It presents a new class of models extending SYK physics to higher dimensions with local lattice couplings and analyzes their critical behavior and chaos properties.

Findings

Stable critical phase in 1+1 dimensions.

Quantum phase transition in 2+1 dimensions.

Maximal Lyapunov exponent $oxed{2 ext{π}T}$ indicating maximal chaos.

Abstract

We introduce a family of Gross-Neveu-Yukawa models with a large number of fermion and boson flavors as higher dimensional generalizations of the Sachdev-Ye-Kitaev model. The models may be derived from local lattice couplings and give rise to Lorentz invariant critical solutions in 1+1 and 2+1 dimensions. These solutions imply anomalous dimensions of both bosons and fermions tuned by the number ratio of boson to fermion flavors. In 1+1 dimension the solution represents a stable critical phase, while in 2+1 dimension it governs a quantum phase transition. We compute the out of time order correlators in the 1+1 dimensional model, showing that it exhibits growth with the maximal Lyapunov exponent $\lambda_L=2\pi T$ in the low temperature limit.